Cast-iron alloy



CLIFTON TAYLOR, OF PITTSBURGH, PENNSYLVANIA,

ASSIGNORS TO MOLYBDENUM CORPORATION OF AMERICA, OF PITTS- A CORPORATION OF PENNSYLVANIA Patented June 3, 1930 UNITED STATES PATENT OFFICE TOLEDO, OHIO, BURGH, PENNSYLVANIA,

AND HERMAN L. GREENE, 0E

CAST-IRON ALLOY No Drawing.

The invention relates to cast iron alloys,

loy which may be easily hardened to a variable degree, and to which a very high degree of hardness may be given, and which may be more readily machined than ordinary cast iron.

In the practice of this invention ordinary cast iron, containing the usual amounts of carbon and silicon has certain amounts of nickel and molybdenum added to it, and contains no other purposely added alloying constituent. The amounts of carbon and silicon present in ordinary cast iron, as here contemplated, are from about 1.0 to 4.0% carbon, and from about .5 to 2.5% silicon. To this there are added nickel from about 1.0 to about 4.0%, and molybdenum not more than about 1.0%. The alloy will of course contain other constituents present as impurities and as incidental to its manufacture from commercial scrap and other materials For example, small amounts of sulphur, phosphorus and manganese may be present as impurities from the pig metal used in a cupola melt, and larger amounts of chromium, vanadium, copper, etc., may be present as constituents found in commercial scrap used also in a cupola melt.

Within the stated ranges of the purposely added alloying constituents, it is preferred to use about 1.5% nickel and about 25% mol bdenum. The content of carbon is preferably about 1.5% and that of silicon preferably about 1.5%."

We have found that! when articles made from the alloy provided according to this invention are cast in permanent or other chill molds, they have a very hi h hardness, ranging from about 700 to 800 l3rinell, and that when cast in sand or other non-chill molds, the have a hardness of about 200 Brinell. lthough the latter is about 50 points higher than ordinary cast iron, we have nevertheless found that the alloy has a dense close grain and that it is more readily machinable than ordinary cast iron.

Having these physical characteristics, the

Application filed April 21,

1927. Serial No. 185,649.

ifs desired to provide with hardened suraces, sired to have relatively soft for machining and other purposes. An example of suc articles is tappets for operating the valves of internal combustion engines. The alloy is also particularly suitable for the manufacture of cylinder blocks and pistons for internal combustion en ines in that it is very resistant to wear, asbut little tendency to grow, and is readily machinable.

According to the patent statutes we have explained the principle of our invention and have described what we now consider to represent its best embodiment.- However, we desire to have it understood that, within the and other portions of which it is de-h scope of the appended claims, the invention may be embodied in cast iron alloys other than that specifically described. e

We claim as our invention:

1. A cast iron alloy consisting of about 1.5% nickel, about 25% molybdenum silicon from about .70 to about 2.5%, an car bon from about 1.5 to about 4.0%, the remainder of the alloy being iron except for constituents present as impurities and as incidental to the manufacture of the alloy.

2. A cast iron alloy consisting of from about 1.0 to about 4.0% nickel, a substantial and eflective amount of molybdenum up to about 1.0%, silicon from about .80 to about 2.5%, and carbon from about 1.5 to about 4.0%, the remainder of the alloy being iron except for constituents present as impurities and as incidental to the manufacture of the alloy.

3. A cast iron alloy consisting of about 1.5% nickel, about 25% molybdenum, about 1.5% silicon, and from about 1.5 to 4.0% carbon, the remainder of the alloy being iron except for constituents present as impurities and as incidental to the manufacture of the alloy.

In testimony whereof, we hereunto sign 

